Hello everybody, DAVDroid lost both of my accounts one time when rebooting, although I installed it from F-Droid and I use CyanogenMod 13.0 (Android 6.0) on my Moto G (falcon). I have got two accounts, one at posteo and one at SOGo (university). The solution so far was to use “DAVDroid Jellybean Workaround”; with that app, I did not have any lost accounts so far. That’s strange, because the workaround app says it would only be needed, if DAVDroid had been installed via Google Play. I just wanted to share that fact, if somebody else gets the same problem. If this problem has been already posted somewhere else, please move / delete it.

@Gruen – I had the same problem with cyngn on zuk z1; solved by clearing fdroid cache & data, then updating fdroid depositories. then reinstalling latest version of davdroid. hope this helps.

There is a problem in F-Droid 0.101-alpha1 with permission for SDK > 23. It even prevented updating F-Droid itself to a version that has the fix. So the fix here is to uninstall F-Droid and reinstall it again from website apk download. Then you can install/update DAVDroid to the newest version.